| Three aspects of the quality characteristic of Green Tea in Shandong, including planting methods,seasonal variation and regional difference were analyzed in this paper.We compared the quality characteristic between Green Tea in Shandong Province and other provinces.The processing of technology was researched in order to improve the quality and reduce the bitter taste of the summer tea.Finally,we analyzed the aroma components of the Green Tea with different aroma types,the results were as follows:1 In the different planting methods.The contents of water extracts,tea polyphonies,catechins,flavone,amino acids and caffeine were 36.66～41.93%, 22.65～27.57%,165.18～174.30mg/g,6.87～12.22mg/g,2.05～3.99%, 3.06～4.17%,and all the contents of quality characteristic of the tea in the open field were the supreme.Compared with the tea in the open field,the content of tea polyphenols was much more higher.The tea in the open field,the contents of flavone,amino acids and caffeine were greatly elevated by 27.05%,13.7% and 9%respectively than winter greenhouse.The highest contents of mineral elements of all the green tea is the tea in the open field,besides,the contents of zinc in the tea of spring greenhouse was higher than the tea of open field.2.The results of biochemical components in the different season showed that:The contents of water extract,tea polyphonies,catechins,flavone,amino acids and caffeine were 34.83～45.36%,24.41～34.28%,173.32～189.97mg/g, 7.67～9.68 mg/g,2.08～4.01%and 3.73～4.58%.Besides,the ratio of tea polyphenols and amino acid was 6.25～16.4.The summer tea had the highest contents of amino acids,and the contents of copper element was 15～39mg/kg, the contents of selenium element was 0.33～0.63mg/kg.3.The results of the biochemistry ingredient in the different tea-growing region of Shandong:In entral shandong tea-growing region and middle south of Shandong tea-growing region,the total quantity of water extract,total quantity of tea polyphonies,total quantity of catechins and the total quantity of amino acids were higher than other tea-growing regions.In the central Shandong tea-growing region and the middle south of Shandong tea-growing region the contents of water extracts were 43.87%and 42.59%,the contents of tea polyphonies were 29.49%and 30.19%;the contents of catechins were163.39mg/g and 157.81mg/g,and caffeine were 4.53mg/g and 4.37mg/g. In the Jiaodong peninsula tea-growing region and the southeast coast tea-growing region,the contents of flavone were higher than other tea-growing regions,which were 9.55mg/g and 8.39mg/g.The analysis of mineral element content indicated that the highest content of element copper in the tea was in the southeast coast tea-growing region,which was 31.25 mg/kg;the highest content of element Iron was393.3 mg/kg in the central Shandong tea-growing region,which was 38.54%and it was higher than Jiaodong peninsula tea-growing region.The element selenium is 0.52 mg/kg in the central Shandong tea-growing region which is higher than others.4.The results of the biochemistry ingredient in the different provinces: The maximum content of the catechins was 174.3 mg/g,the content of flavone was 7.67 mg/g,the content of amino acids was3.79%,and the content of caffeine was 3.82%in green tea of Shandong.The contents of flavones which were 1.59,1.36,1.33 and 1.31 times higher than the Zhejiang,Anhui,Hubei, and Shanxi,and the contents of amino acids which were 1.28,1.68,1.24 and 1.65 times higher than the Zhejiang,Anhui,Hubei and Shanxi province.The maximum contents of Fe and Mg were found in Shandong province,and the maximum content of the content of Se was1.28mg/kg in Shanxi.5.The optimal process technique was as follows,fresh leaves→spreading time(6h)→steam-fixation→first rolling→bake for first time→second rolling→flying and backe.The results showed that it was the optimum process. Study on the removal of astringency of summer tea,the results showed that spreading time could decrease anthocyanidin content and increase Amino Acid and lavonoids content.Besides,the methods of deactivation of enzymes had some influences to the removal of astringency of summer tea,and the killing green and evaporating green effects was the best. 6.The 78 volatile components were identified and determined.The endemic aroma components of green tea of flowery flavor werel-Pentanol,.beta.-Terpineol,α-limonene,trans-3-Hexenyl butyrate, trans-3-Hexenyl butyrate.The endemic aroma components of green tea of clean aroma was Octane-3-Alcohol 1,2,3,7-Trimethylheptane,beta-Ionone, 7-methyl-hexadecane.The endemic aroma components of green tea of High-fire was 3-methyl-1-Pentanol,2,3,4-Trimethylheptane,hexenylfuranone, 5-methyl thiazole,5-methyl-6-ethyl Dodecanese.The endemic aroma components of green tea of chestnut flavor was 1-hexanal,4- methyl Decane,3- methyl Undecanel,2,3-Diethyl Undecanel,3,7-dimethyl Decane, 3,8-Dimethyl Undecanel.The endemic aroma components of green tea of chestnut flavor was 2-ethyl- 2-hexanone,Benzyl methyl ketone,1, 2-s-5-oxygen-cycloheptane. |
